Well done, that has inspired me to work out how to use the cruise control on my car too. It’s amazing what we can do when we have to, and I know how hard it is to suddenly have to work out all those little things someone sle has been doing. You have a right to feel proud of yourself. 
My mother was widowed at 85. She never drove, leaving that to my dad, and in fact was known to drop off to sleep as soon as she was settled in the passenger seat. After he died she took some refresher driving lessons, bought herself a small, easy to park car, and now drives herself to U3A meetings, church, various committees etc.